Oil well drilling apparatus

ABSTRACT

The pump of a supply of drilling mud is connected to the drill stem and a volume chamber is connected to a point between the pump and stem. A gas system for replenishing the chamber and a liquid system for washing mud from the interior of the chamber are also disclosed.

United States Patent 1 1 3,682,262 Guier 1451 Aug. 8, 1972 [54] OIL WELL DRILLING APPARATUS 1,801,788 4/1931 Zublin ..175/205 X 72 Inventor; William Gui, 3100 East 71st St 2,803,432 8/1957 Teichmann et a1....175/205 X T l Okla 74114 3,534,822 10/1970 Cambell et a1 175/205 X [22] Flled: June 1970 Primary ExaminerDavid H. Brown [21] Appl. No.1 47,439 Attorney-Arthur L. Wade 52 US. Cl. ..175/205, 175/217, 175/218 [57] ABSTRACT Cl- The pump of a of mud is onncced Fldd Search "175/205, 216-218 the drill stem and a volume chamber is connected to a point between the pump and stem. A gas system for [56] References and replenishing the chamber and a liquid system for UNITED STATES PATENTS washing mud from the interior of the chamber are also discl sed. 2,310,001 2/1943 Haddock ..l75/205 0 2,082,329 6/1937 Foran et a1 ..175/205 X 4 Clains, 2 Drawing Figum PATENTEDmc 8 m2 F E-E? IN VEN TOR h ////am Ga/er BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to systems for supplying drilling mud to strings of drill pipe. More particularly, the invention relates to providing a supply of gas to the system with which to clear mud from inside the joint of the string to be broken.

2. Description of the Prior Art In present rotary drilling practice, the drill pipe is hoisted up to drain the mud from the joint to be broken. If the orifices in the bit are small, or the mud is high in viscosity, the driller, or hoist operator, will often drop the pipe and catch it on the brakes in order to apply the force of momentum of the fluid to force the fluid out of the bit orifices. Obviously, this practice can ilamage the pipe; the pipe could even be parted and This art has long needed a means to chase the mud from the rotary hose, swivel and kelly to well below the point where the joints of pipe are to be unthreaded. The beneficial results would be obvious. If the mud is chased quickly and automatically when the mud pump is shut down, time will be saved and there will be less mud sprayed about the drilling floor. Speed and safety will be attained.

SUMMARY OF THE INVENTION A principal object of the invention is to purge the drill string of drilling mud as desired.

Another object is to apply a gas source to push the mud down the drill string and past the unthreading location.

Another object is to automatically replenish gas which has been expended in moving the mud as desired.

Another object is to utilize a gas source for moving the mud and also utilize the gas source as a vibration dampener, or to augment other vibration-dampening means, for the mud pump.

Another object is to automatically clean mud from the apparatus supplying gas.

The present invention contemplates a source of gas connected at a strategic location between the mud pump of a rotary drilling system and the joint of the drill string to be unthreaded and as close to the unthreading location as practical. The gas is held under compression by the pump. When the pump is shut down, the gas expands from the source and purges the mud from the source connection to downstream of the unthreading location.

The invention further contemplates the source of gas as a chamber in which the gas is held under compression by the mud forming a piston within the chamber.

The invention further contemplates a supply of gas connected to the chamber when the pump is again started to replace the gas expended down the string when mud has been pushed past the joint which is unthreaded.

The invention further contemplates the chamber of gas compressed by the mud functioning as a vibration dampener during normal functioning of the mud pump.

The invention further contemplates the chamber being supplied a cleaning fluid as it is being replenished with gas and again subjected to the pump pressure after having purged mud in accordance with the objects of the invention.

Other objects, advantages and features of this invention will become apparent to one skilled in the art upon consideration of the written specification, appended claims, and attached drawings, wherein: FIG. I is an elevation of the drilling floor, string, kelly, swivel, hose and pump system embodying the invention; and

FIG. 2 is a sectioned elevation of the upper part of the chamber of gas in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODI- MENT Referring to FIG. 1, there is disclosed a drilling floor l. The upper joint 2 of drilling pipe is threaded to the kelly 3 and their box and pin are raised above the floor l. The kelly bushing 4 is about the lower portion of the kelly and the upper portion of the kelly has swivel 5 mounted on it.

Elevators 6 attach to the swivel and are controlled by the hoist and drawworks whose disclosure is not necessary to an understanding of the invention. However, the drilling mud pump 7 is disclosed near the level of the drilling floor l. The pump is shown as supplying mud from reservoir 8 and being driven by motor 9 to draw mud from the reservoir and discharge the mud to conduit 10.

The pressure at which mud is discharged from pump 7 is many hundreds of pounds per square inch. Conduit 10 is a high-pressure line, extending as a standpipe up to a fixture 11 which connects to swivel 5 by flexible hose 12. Flexible as hose 12 is, it is fabricated to contain the high pressure discharge of pump 7.

In operating the string of drill pipe, the hoist raises and lowers the swivel 5 relative to the fixture 11. Therefore, flexible hose 12 becomes the link through which mud is supplied the swivel, kelly and drill stem as the string is raised and lowered in the drilling operation.

FIG. 1 demonstrates the critical problem which the present invention solves. Kelly 3 and pipe 2 must be disconnected so another section of drill pipe can be added. If the drilling mud has not drained out of kelly 3, it will spray over the table 1 when the box and pin of the pipe and kelly are unthreaded. What is needed when it is time to unthread pipe 2 from kelly 3 at this location is a means for positively purging the kelly of mud to downstream of the location.

A plunger of gas is provided by the present invention to force drilling mud from hose l2 and kelly 3, down past the threaded juncture of the kelly and pipe 2. This gas is provided from tank 20. Compressed under high pressure, the gas from this tank will force the mud from hose l2 and kelly 3 when pump 7 is stopped and the bit is lifted to the position indicated by the kelly and pipe illustrated in FIG. 1. There remains the problem of control of the gas in tank 20.

A supply of gas for tank 20 is connected to the system by line 21. Line 32 is controlled by manually operated valve 22. Line 23 connects to line 21 which conducts the gas to the top of tank 20. This gas can only flow into tank 20 because check valve 24 in line 23 prevents reversal of the flow. The next consideration is when valve 22 is operated to flow gas into tank During drilling, pump 7 is flowing mud to the bit at the endof the string of drill pipe. This flow of mud is halted when the string is drawn to the FIG. 1 position for the addition of another section of drill pipe. Therefore, when the mud pump is stopped, the purge of kelly 3 with the gas tank 20 should take place.

When pump 7 is stopped, the flow of mud in conduit 10 is halted. The pressure of the gas in tank then takes over in that it is behind the inventory of mud between fixture ll, hose l2, kelly 3, pipe 2, and the bit onthe end of the string. This gas of tank 20 continues the flow of mud along 12, 5, 3, and 2 and out of the bit.

' If the capacity of tank 20 is sufiicient, the mud will be 20 automatically takes over control of the mud. The

gas expands and much of it moves along hose 12 and kelly 3. When pump 7 starts again, the air past fixture l l is cut off and pushed ahead of mud from conduit 10. Therefore, there is a significant loss of gas from tank 20 each operation.

As previously set forth, gas to charge tank 20 comes from line 21. Line 21 connects to line 23 and line 25. Line 25 applies the source of gas to switch 26 which controls motor 9. When pump 7 is started, mud flows in conduit 10, through fixture ll, hose 12 and kelly 5. At the sametime, gas is flowed into the top of tank 20 to replace the gas which passed from tank 20 beyond fixture 11.

It may be desirable to establish a check valve in the top of tank 20 to further insure unidirectional flow of all fluids into the tank. A valve for this purpose is mounted at 27 and connected to both gas line 23 and a line 28 for liquid.

Liquid is supplied tank 20 through line 28 connected to a supply of liquid. At the proper time, liquid is flowed into the valve 27 along with gas from line 23.

- This liquid will clean the internal parts of valve 27 and wash mud from the internal walls oftank 20.

The system of liquid supply is arranged to inject a predetermined quantity of liquid into tank 20 each operation of valve 22. The predetermined quantity is fixed by the capacity of a cylinder 30 in which a piston 31 is reciprocated. When filled with liquid and connected to line 28, cylinder 30 has its piston 31 actuated by the gas of supply line 21 to push its liquid along line 28. Line 32 is connected to valve 22 to provide the gas of line 21 for this purpose.

Liquid for cylinder 30 is provided by line 33 which is connected to cylinder 30 through check valve 34. When line 32 is disconnected from line 21, piston 31 is returned to the position shown by the pressure of liquid from line 33. When valve 22 reconnects line 32 to line 21, piston 31 is moved upward and the liquid above the piston moves along line 28 through valve 27 to wash the valve and the inside of tank 20.

, As valve 22 simultaneously applies the gas pressure of line 21 to line 23 and line 32, gas and liquid are flowed in parallel to tank 20. It may be desirable to first sure relief valves 35 and 36 are mounted in gas line 23 and liquid line 28. Liquid relief valve 36 can be set to open at a pressure lower than the pressure at which valve 35 will open. The result is a flow of a finite amount of liquid into tank 20 before a flow of gas.

FIG. 2 is established to disclose a satisfactory form of valve for 27 on the top of tank 20. The line 37 is communicated with the interior of tank 20 through a seat 38. A flexible, flat valve element 39 is mounted inside 27 to position relative seat 38. Holes 40 are formed through valve 39 to allow passage of fluids from line 37 once past seat 38. I

When fluids do not flow into tank 20, valve 39 is against seat 38 as shown. When fluids flow through line 37, valve element 39 flexes downward and the fluids flow through holes 40 and into tank 20, washing the valve element and replacing the gas lost past fixture l 1. If the valve element 39 is formed of soft rubber its expansion and contraction when it operates will help fluff off any wet or dry mud which may accumulate upon it. Finally, valve 27 and check valve 24 are located as high as practical in the system so the mud and fluids will drain by gravity and tend to obviate these valves plugging with solid material which will drain from them by gravity.

CONCLUSION Although tank 20 is disclosed as mounted on fixture 11, the concept of the invention is to broadly apply the necessary gas pressure to any point along conduits 10,12 which will serve the purpose of chasing, or removing, mud from the joint to be broken in the drill string. Tank 20 could be mounted on swivel 5, as an example. In all such arrangements, it is to be clear that the concept of the present invention is not to be limited to any specific location or connection although it should be as close to the unthreading location as practical.

From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope f the invention. I

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted in an illustrative and not in a limiting sense.

The invention having been described, what is claimed is: I

l. A system for supplying drilling mud to a string of drill pipe, including,

a reservoir of drilling mud,

a pump connected to the reservoir to withdraw drilling mud,

a conduit connected at one end to the pump to receive the drilling mud,

a string of drill pipe connected to the other end of the conduit to receive the drilling mud from the con duit,

a tank of gas connected to the conduit at a point between the connection to the pump and the string of drill pipe through which the gas is compressed by the drilling mud when the pump delivers mud to the conduit and through which the compressed gas expands to force mud from the connection of the source to the conduit down the string of drill pipe a predetermined distance when the pump is stopped, a supply of gas, and means for connecting the supply of gas to the tank when the pump is actuated to replace gas lost downstream of the tank connection to the conduit.

2. The system of claim 1, including,

a source of liquid a source of liquid,

and means for connecting the source of liquid to the tank when the pump is actuated to wash mud from the interior of the tank and valves on which mud accumulates.

3. A system for purging drilling mud along a well drilling string and past an unthreading location in the string, including,

a drilling string including a threaded joint which it becomes desirable to unthread,

a pump connected to the string to supply drilling mud,

a tank connected to the string at a point as close as practical to the joint to be unthreaded,

a charge of gas within the tank which will compress under the pressure of the drilling mud when the pump is running and expand when the pump is stopped to push drilling mud past the joint to be unthreaded,

a supply of gas to be connected to the tank and replace, the gas charge lost when drilling mud is pushed past the unthreaded joint, and a valve with which to connect the supply of gas to the tank and apply the supply of gas to start the pump.

4. The system of claim 3 including,

a supply of liquid connected to the tank and controlled by the gas applied by the valve to flow liquid from the supply into the tank to wash the tank interior,

a first relief valve connected between the valve applying the gas of the supply and the tank,

and a second relief valve connected between the supply of liquid and the tank, the first and second valves arranged to flow liquid into the tank to wash the interior before gas is flowed into the tank to replace the gas charge lost in pushing drilling mud. 

1. A system for supplying drilling mud to a string of drill pipe, including, a reservoir of drilling mud, a pump connected to the reservoir to withdraw drilling mud, a conduit connected at one end to the pump to receive the drilling mud, a string of drill pipe connected to the other end of the conduit to receive the drilling mud from the conduit, a tank of gas connected to the conduit at a point between the connection to the pump and the string of drill pipe through which the gas is compressed by the drilling mud when the pump delivers mud to the conduit and through which the compressed gas expands to force mud from the connection of the source to the conduit down the string of drill pipe a predetermined distance when the pump is stopped, a supply of gas, and means for connecting the supply of gas to the tank when the pump is actuated to replace gas lost downstream of the tank connection to the conduit.
 2. The system of claim 1, including, a source of liquid a source of liquid, and means for connecting the source of liquid to the tank when the pump is actuated to wash mud from the interior of the tank and valves on which mud accumulates.
 3. A system for purging drilling mud along a well drilling string and past an unthreading location in the string, including, a drilling string including a threaded joint which it becomes desirable to unthread, a pump connected to the string to supply drilling mud, a tank connected to the string at a point as close as practical to the joint to be unthreaded, a charge of gas within the tank which will compress under the pressure of the drilling mud when the pump is running and expand when the pump is stopped to push drilling mud past the joint to be unthreaded, a supply of gas to be connected to the tank and replace, the gas charge lost when drilling mud is pushed past the unthreaded joint, and a valve with which to connect the supply of gas to the tank and apply the supply of gas to start the pump.
 4. The system of claim 3 including, a supply of liquid connected to the tank and controlled by the gas applied by the valve to flow liquid from the supply into the tank to wash the tank interior, a first relief valve connected between the valve applying the gas of the supply and the tank, and a second relief valve connected between the supply of liquid and the tank, the first and second valves arranged to flow liquid into the tank to wash the interior before gas is flowed into the tank to replace the gas charge lost in pushing drilling mud. 